Preheater for internal-combustion engines



Filed Dec. 21, 1951 W Y a V w Patented June 15, 1954 PREHEATER FORINTERNAL-COMBUSTION ENGINES Louis M. Kazial, Minneapolis, Minn, assignorof one-fourth to Thomas W. Walsh, one-fourth to Frank J. Thill, andone-fourth to John J. Nozel,

all of St. Paul, Minn.

Application December 21, 1951, Serial No. 262,683

5 Claims.

This invention relates to pre-heaters for internal combustion engineshaving a fluid circulatory system and more particularly to a permanentlyinstalled pre-heater which is adapted to be maintained in standbycondition during nonuse of the engine.

It is a principal object of the invention to provide for a pre-heaterwhich will be mounted for continuous standby use closely adjacent theengine and which will function in an efficient man ner to economicallymaintain an internal combustion engine in condition for ready starting,even when the surrounding air is extremely cold.

It is a further object of the invention to provide for a pre-heater forinternal combustion engines in which only that portion of thecirculating cooling fluid lying within the engine itself and the heatexchanger will be heated and circulated by convection currents, while atthe same time ire-conditioning the air intake device on the engine sothat the first quantity of cool air entering the engine during startingwill be pre-heated to likewise assist in easy starting.

It is a still further object to provide my preheater with a main burnerelement adapted for ignition by a pilot light which will bring theentire engine, including the air intake device, to a conditionapproximating that of summer weather for easy starting of said engine.

These and other objects and advantages of the invention will more fullyappear from the following description made in connection with theaccompanying drawings, wherein like reference characters refer tosimilar parts throughout the several views, and in which:

Fig. 1 shows a side elevation of a typical internal combustion engine ofthe diesel type to which is attached my pre-heater element in adjacentrelation therewith;

Fig. 2 is a detailed View of the heat exchange portion of my pre-heaterin side elevation with portions at the top and the bottom in verticalsection to show more clearly the internal structure thereof; and y Fig.3 is a horizontal section of the heat exchange element shown in Fig. 2looking in the direction of arrows 3. I

The internal combustion engine, which may be of the diesel type, isshown in Fig, 1 and indicated generally by the letter E. The engine E isequipped with the usual fluid circulatory cooling system which comprisesa fluid pump (not shown), internal channels for the tortuous travel ofcooling fluid for contact with the internal walls of the engine, a fluidconnector It interposed between the upper part of the engine E and thetop of radiator H, the internal coils of the radiator H (not shown), anda lower connection l2 between the radiator i I at the lower part of theengine E to complete the fluid system. A thermostat of ordinaryconstruction may be interposed between the radiator ii and the engine Eas at it. A fan it of ordinary construction is interposed between theengine E and the radiator H. In the ordinary operation of the engine Ein warm weather, the pitch of the fan blades are as shown in Fig. 1 andthe disposition of the exhaust of my invention in relation to the aircurrents created thereby is predicated upon the assumption that thepitch of the fan will remain the same and will operate in the directionof the arrow adjacent fan belt i5. It is understood, however, that insome engines and more particularly in the diesel type of engine the fanl4 may be replaced with a fan having the blades pitched in reverse so asto blow air through radiator II, which air has been partially heated byproximity to the engine E, rather than sucking in the completely coldatmospheric air as would be the case where the pitch remains the same asthat illustrated.

My invention comprises a heat exchanger shown in detail in Fig. 2 whichis indicated generally by the letter H. The heat exchanger has an outercasing it which is Waterproof and tight at all of its joints. Disposedinternally near the top thereof is a header plate ll and near the bottomthereof is header plate it. A chamber [9- is created thereby at the topof the casin i5 and combustion chamber 29 is formed at the bottom of thecasing i6. Interposed between the headers i1 and it are heat exchangetubes 2! so that the chambers 26 and is are in communicationtherethrough. The opening 22 is formed at the top of the casing it toform an outlet for exhausting gases which pass upwardly through thetubes 21 and into the chamber i9. The space surrounding th heat exchangetubes 2! and lyin between header plates 5! and it constitutes the liquidcontaining portion of the heat exchanger. The liquid circulatingtherethrough enters at the lower portion thereof through connector 23and out of the top through connector 2 3. It is understood, of course,that cool liquid entering the com nector 23 will be heated and will riseby convection currents so as to circulate through the heat exchanger Hand out or the connector 24. Die.- posed Within the chamber 26 is aburner element 25 which has orifices 25 as shown through the cutawayportion of Fig. 2. Communicating with the burner element is a pipe 21and an air mixer 28. The air mixer in turn has disposed therein a nozzle29 through which gaseous fuel may flow from a source of supply as at 3Bin Fig. 1. I have found that propane gas is useful for my purpose sinceit will vaporize sufficiently even in cold weather to operate my burner25 and still will not acquire too great an internal pressure within thesupply tank 30 during warm weather. A control valve 3! is interposedbetween the connectin line 32 and the nozzle 29 so as to vary the amountof fuel supplied the burner 25. The valve 3| has a lever 33 Which may beoperated remotely from a panel board 35 through which a manual cableelement 35 is attached to a control such as knob 38. it is understood,of course, that the control 38 may be in the form of a dial or othermanual means for causing the lever 33 to move to various positions.Connecting with the fuel supply line 32 and unaifected by the valve 3|is a small tube 3?. This tube terminates in an orifice 38 to supply fuelto a pilot light for continuous burning whether or not the burner 25 islit. Closing off the bottom of the outer casing 16 is a plate 39 whichmay be attached thereto as by thumb nuts 45. It may be seen that theburner 25 is thus completely enclosed within the casin l6 and the firehazard from accidental ignition of as and oil upon or around the engineis thus minimized.

Referring now to Fig. l the heat exchanger H is mounted in an upstandingmanner at the side of the engine E and is equipped with a liquidconnector ll which extends from the outlet pipe 2% to the connector 32communicating with the internal cooling channels at the upper part ofthe engine E. Likewise, inlet pipe 23 at the bottom of heat exchanger Hcommunicates through connectcr 3 with the internal channels at the lowerpart of the engine E. At the exhaust opening 22 a structure 5, definingan enclosed channel and supporting means, communicates therewith forconducting exhaust gases from the casing 16 to the atmosphere. In itspreferred form this structure is a metallic tube l i having good thermalconducting properties. The air intake manifold lies in a horizontalmanner near the top of the engine E. The metallic tube 44 is fastened tothe intake manifold 45 by metallic supports 46 so as to establish athermal conduction between the tube 44 and the manifold 45. The metallictube is may likewise be in thermal contact through supports 48 with theair cleaners Q1 which communicate with the intake manifold 45. Duringnormal running operation of the engine heat caused by combustion thereofwill be transmitted to the air intake manifold and thus assists inpreheating the air. It is obvious, of course, that when the engine hasbeen stopped for some time in cold weather the intake manifold will bechilled and will not serve to pro-heat the air until such time as theentire engine becomes warm. With my device, however, the intake manifoldis maintained in a warm condition at all times and the air comintherethrough will be immediately pro-conditioned for starting withouthaving to wait for the engine to be warmed in its entirety. The end 49of metallic tube A l is reversed in direction so that the opening alignssubstantially with the direction of air flow from the fan M as shown inFig. 1. It is, of course, understood that where the pitch of the fan isreversed as previously described, the end at will be oriented in theopposite direction. The reason for this is to prevent burner or pilotlight during the running of the engine which choking will, of course,upset the air and gas ratio established at the flame and may evenextinguish the flame if not corrected for as described. It is understoodthat where space conditions are favorable the end 49 may extend upwardlyif out of the air flow from the fan 14.

In the operation of my device the pilot light 38 is lit and remains litcontinuously during the cold weather starting period. The flame at theend of pilot light 38, even though small, will take the chill oi? thecirculating fluid and under normal circumstances will make it possiblefor the engine to start, although not in the easiest manner. When it isdesired to pre-condition the engine for easy starting the operator mayadjust the control knob 36 so as to cause the burner 25 to light whenfuel, such as a hydrocarbon gas from supply tank 28, is metered throughvalve 3!. Under normal circumstances the burner 25 is lit for apredetermined period before attempting to start the enine. In extremelycold weather, however, the burner 25 may be kept with an intermediateflame throughout the entire period between stopping the engine andstarting it again. The device is flexible enough to admit of severalprocedures according to the severity of the weather conditions.

It is thus seen that I have provided a preheater for internal combustionengines, especially of high compression types, in which the circulatingfluid warms the entire engine, thus making lubricating oil more fluid,and at the same time pro-heats the air intake device so that the firstair which reaches the combustion chambers will not be chilled so as toprevent ignition.

It will, of course, be understood that various changes may be made inthe form, details, arrangement and. proportions of the various partswithout departing from the scope of my invention.

What I claim is:

1. In a pro-heater for conditioning prior to starting thereof in coldweather an internal combustion engine having a front circulatory coolingsystem and an air intake mechanism, the combination of an upstandingfluid heat exchanger mounted closely adjacent a side of said engine andhaving liquid communication with said cooling system of the engine froma lower position thereat through the fluid heat exchanger to an upperposition at the engine, and having a passageway for combustion gasestherethrough in a thermal exchange relationship with said liquid, 2.fuel burner positioned at the lower portion of said heat exchanger andconnected with a source of fuel supply, an extension of said passagewaydefining an enclosed channel for leading exhaust combustion gases fromsaid heat exchanger to the atmosphere, and a thermal connector joiningsaid extension with said air intake mechanism for thermal conductionthereacross whereby said engine will be thermally conditioned for readystarting not withstanding cold ambient temperatures.

2. In a pre-heater for conditioning an internal combustion engine havinga fluid circulatory cooling system, prior to starting thereof in coldweather, the combination of an upstanding fluid heat exchanger mountedclosely adjacent a side 1 of said engine, having liquid communicationwith said cooling system of the engine from a lower position at theengine through the fluid heat exchanger to an upper position at theengine, and having a passageway for combustion gases choking of theexhaust gases of the pro-heater therethrough in a thermal exchangerelationship with said liquid, an intake manifold and an air cleanercommunicating therewith on the engine, a fuel burner at the lowerportion of said heat exchanger connecting with a source of fuel supply,a structure defining an enclosed channel for leading exhaust combustiongases from said heat exchanger to the atmosphere, a thermal connectorjoining said structure with said intake manifold and said air cleanerfor thermal conduction thereto whereby said engine will be thermallyconditioned for ready starting notwithstanding extremely cold ambienttemperatures.

3. In a pre-heater for an internal combustion engine having acirculatory fluid cooling system, the combination with internal channelsdefined by the walls of the engine, a radiator for cooling the fluid, afluid connection between the upper portions of the radiator and theengine channels and between the lower portions of the radiator and theengine channels, a thermostat for restricting the flow of cooling fluidinterposed between said radiator and said channels, and an air intakemanifold; of an upstanding heat exchanger mounted closely adjacent theside of said engine, said heat exchanger having fluid communication withsaid internal channels, a fuel burner connected to a source of fuel forheating said fluid, and an exhaust opening at the top of said heatexchanger for egress of the exhaust gases from said burner, an exhaustpipe attached to the heat exchanger for communication with said opening,and mounting means having high thermal conductivity for at taching saidexhaust pipe to an area of said intake manifold for transferring heatfrom exhaust gases of said burner through said exhaust pipe and to saidintake manifold, whereby said intake manifold and that portion of thecirculating fluid within the engine and heat exchanger will bepro-conditioned for easy starting of the engine.

4. In a pre-heater for an internal combustion engine having acirculatory fluid cooling system, the combination with internal channelsdefined by the walls of the engine, a radiator for cooling the fluid, afluid connection between the upper portions of the radiator and theengine channels and between the lower portions of the radiator and theengine channels, and a thermostat for restricting the flow of coolingfluid interposed between said radiator and said channels, and an airintake manifold; of an upstanding heat exchanger mounted closelyadjacent the side of said engine, said heat exchanger having fluidcommunicat1on with said internal channels, a. fuel burner connected to asource of fuel for heating said fluid, a pilot light connected to saidsource of fuel, and an exhaust opening at the top of said heat exchangerfor egress of the exhaust gases from said burner, a control foroperating said burner, an exhaust pipe attached to the heat exchangerfor communication with said opening, and mounting means having highthermal conductivity for attaching said exhaust pipe to an area of saidintake manifold for transferring heat from exhaust gases over saidburner through said exhaust pipe and to said intake manifold, wherebysaid intake manifold and that portion of the circulating fluid withinthe engine and the heat exchanger will be pre-conditioned for easystarting of the engine.

5. In a pre-heater for an internal combustion engine having acirculatory fluid cooling system, the combination with internal channelsdefined by the walls of the engine, a radiator with rotatable fanadjacent thereto for cooling the fluid, a fluid connection between theupper portions of the radiator and the engine channels and between thelower portions of the radiator and the engine channels, a thermostat forrestricting the flow of cooling fluid interposed between said radiatorand said channels, and an air intake manifold; of an upstanding heatexchanger mounted closely adjacent the side of said engine, said heatexchanger having fluid communication with said internal channels, a fuelburner connected to a source of fuel for heating said fluid, a pilotlight for igniting said fuel burner, and an exhaust opening at the topof said heat exchanger for egress of the exhaust gases from said burner,a control for operating said burner, an exhaust pipe attached at one endto the heat exchanger for communication with said opening and at theother end open tothe atmosphere in the direction of air movement throughsaid fan, and mounting means having high thermal conductivity forattaching said exhaust pipe to an area of said intake manifold fortransferring heat from exhaust gases of said burner through said exhaustpipe and to said air intake manifold whereby said air intake manifoldand that portion of the circulating fluid within the engine and heatexchanger will be pre-conditioned for easy starting of the engine.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,246,727 Donning Nov. 13, 1917 1,357,598 Thompson Nov. 2,1920

